10 great traditions

Arguably one of the most iconic scenes in all of college football, Clemson players rub "Howard's Rock" for good luck before they race down the hill and onto the field at Clemson Memorial Stadium before every home game.

An Iranian military observation aircraft flew within 50 yards of an armed U.S. Navy helicopter over the Persian Gulf this month, sparking concern that top Iranian commanders might not be in full control of local forces, CNN has learned.